Making modifications to an existing system such as an existing aircraft generally requires examinations and modification of legacy design drawings. For example, the B-52 aircraft is expected to have an operating life in excess of 80 years, where original legacy drawings for the B-52 aircraft may be scanned hand drawings. More commonly, existing passenger aircraft designs may be converted to freight operations. A maintenance engineering engineer, mods engineer, or freighter conversions engineer may need to compare two different versions of drawings stored in a database, and document results of their findings for future use. The drawings are often very complex and therefore, it can be very time-consuming to discover and locate a change that has been made.
Currently, users spend a considerable amount of time performing a visual inspection of two sets of drawing pictures either via printouts of the drawings or by displaying both drawings on a monitor and switching back and forth until they find all the differences. It can be quite easy to miss some changes in a very complex drawing. In freighter conversions, engineers may try to capture their conclusions in spreadsheet form, but often the spreadsheet information is delayed because of work pressures, and therefore the spreadsheet information can be easily misplaced or not updated in a timely manner.